Graham Mackrell, managing director of Harmonic Drive UK, looks at how collaborative robotics is changing the way robots are helping the human workforce.
The release of Sphero's impressive BB-8 Droid toy raised anticipation ahead of last December's premiere of Star Wars: Episode VII The Force Awakens, and it is easy to see why. Not only is the little droid entertaining, it speaks to our desire to increase our interaction with technology – and to have useful robots at hand to help out. This is not necessarily a new concept in industrial, automation or medical settings, but it is advancing.
For a long time, the idea of a helpful robot that was an active member of your 'Rebel Alliance' was confined to science fiction. In the real world, robots have been mechanical beasts locked away in cages, a tool to be used and controlled by an engineer. However, science fiction is slowly becoming science fact as we let the robots out of their cages.
There is no denying the paradigm shift that has taken place with regards to how we view robots. Rather than seeing just one arm bolted to the floor, we are seeing Honda's Asimo robot navigating steps and MIT's robotic cheetah leap over hurdles. These have transitioned from gimmicks to actual applications in manufacturing plants, automated processes, and even operating theatres, and there are now very advanced applications sitting alongside the traditional six-axis (anthropomorphic), SCARA (selective compliance articulated robot arm) and Cartesian robots we are used to.
Robots are now being designed with collaboration in mind, making them part of the team. This is driving increased accuracy and productivity for many businesses, as well as making it safer than ever before to work in the same space as robots – without a cage. The fences are coming down.
Part of the team
Collaborative robots are designed, as the name suggests, to operate in the same workspace as the human workforce. Instead of no-go areas dominated by machines, we will start to see robots and humans working side by side. Lightweight, dexterous and easy to operate, the new wave of robotics wants to be part of the team.
A relative celebrity among existing collaborative robots is Baxter. Rethink Robotics launched Baxter in 2012 and the dual-armed robot has garnered quite a lot of attention, not least because its affordable price starts at around £20,000.
Baxter has two seven-axis arms, a torso and an LCD display that acts as a 'face', even reacting to human interaction. With sonar, camera sensors and integrated vision for object detection built in it is able to understand when there are humans in its space. Baxter even works by applying some good old fashioned common sense, being put to use for tasks such as examining parts to see if they meet specifications and then placing them in either 'pass' or 'reject' piles.
Keeping human colleagues safe
Robots like Baxter are relatively lightweight compared with their non-collaborative cousins, and many are intended to be used directly alongside human workers. This has obviously generated much debate around health and safety.
As recently as July 2015, the rocky relationship between automation and people hit the headlines after a 22-year-old man was tragically killed in an incident involving a robot. Investigations concluded that it was simply a tragic accident and the robot, which was not a collaborative machine, was not at fault. And yet, it had many people taking a second glance at how safe employees would be if these machines were integrated into the workforce.
The International Standards Organisation (ISO) has several standards concerning the use of robots, including ISO 10210-1 Safety of Industrial Robots, ISO 10210-2 Safety of Industrial Robot Integration, and ISO 13482 which outlines performance criteria relating to safety for personal care robots.
Within the ISO standards there are four key aspects that govern human–robot collaboration. Stopped state monitoring states that a robot should stop when a human enters a scanned area and continue to monitor until the person leaves the space before starting again; speed and separation monitoring standards state that robot must slow down when a human comes near and should stop if a human comes too close.
The hand-guiding directive explains that a person should be in direct contact with the robot while they are guiding or 'training' it and, with regards to power force limiting, the ISO standards outline that safety should be achieved by restricting the amount of force available in the system through electrical means or mechanical compliance.
ISO Technical Specification ISO/TS 15066
More recently, in February 2016, ISO published ISO/TS 15066:2016 Robots and robotic devices. Collaborative robots. This is not a formal standard but a supplementary document that supports the two parts of the existing standard ISO 10218 Safety Requirements for Industrial Robots, part 1 being Robots and part 2 being Robot systems and integration. ISO/TS 15066 will help integrators of robotic cells conduct risk assessments when installing collaborative robots.
However, there is a reason that the payload in existing collaborative devices is restricted to around 10kg (22 pounds) and the speeds are a far cry from traditional flexpickers or six-axis machines. Anything bigger and faster is prohibited under the regulations.
And yet, manufacturers of collaborative robots are using technology to go above and beyond the expected. For instance, industry-leading single-arm robots address power and force limits using torque sensing. This means that apparatus knows when it encounters a human being or another object, and when it recognises an increase in torque force or force required for movement, such as in a collision, the arm stops before it can cause harm.
Rethink Robotics has described Baxter as being 'self-evidently safe' thanks to its detailed design with completely back-drivable joints, force sensing and pinch points. The device is aware of the slightest contact with a person and not only stops in response to the touch, but also moves back. This function is achieved thanks to series elastic actuators that use a spring to flex the joints and allow Baxter to 'judge' the force being applied and react accordingly.
To ensure consistent, reliable reactions in these types of situations the gears and drives in the robot have to be of the highest quality. It does not matter how reliable the sensors are if the robot arm itself cannot stop or move as it should. That is why companies use high-precision gears such as those manufactured by Harmonic Drive. These gears allow for highly accurate movements that can be repeated again and again with precision.
This level of accuracy and repeatability gives reliable peace of mind that collaborative robots can be relied upon to react to their surroundings.
Technological advances have also made collaborative robots easy to operate and 'teach'. Rather than employing an engineer to programme and run robots, collaborative devices can be led by the wrist and 'taught' what is expected of them, or operated using very straightforward menus. Any member of staff can be trained in their operation in short amount of time.
Imagine being able to rest easy in the knowledge that the robots in your facility react to keep your lone worker safe and that the same lone worker is confident and able to control the machine without support. Is that not the true essence of productive, safe collaboration between man and machine?
Carry on Doctor
As well as keeping their colleagues safe, collaborative robots are helping people who are sick or injured. In fact robots have been used in operating theatres across the globe for quite a while now, and they have been doing a rather good job – no matter what scaremongers would have you believe.
Academics in the USA recently conducted a study into the safety of surgical robots that linked these devices to around 144 deaths and roughly 1000 injuries in a 14-year period in America. However, this is out of a total number of operations that was in excess of 1.7 million! Not bad statistics when you take everything in context – and robots have come a long way in those 14 years.
The use of robotics in this context is yet another example of how these machines serve to augment and not replace the knowhow and experience of human beings. Surgery is physically demanding for surgeons, who often succumb to the strain placed on backs, shoulders and necks and are forced to retire in their mid to late 50s.
The addition of machines such as the popular Da Vinci robot to theatre teams enables doctors to perform complex procedures in a seated position, controlling the robot from a console. This not only extends their career, it also enables healthcare providers to benefit from the knowledge and expertise of seasoned staff for longer.
Patients benefit from this approach too. Keyhole surgery can be tricky for human hands to perform as the apparatus used is awkward to handle. A robot arm is steady and more easily directed. Increased precision and faster surgery that is minimally invasive, reduces both trauma to the patient and overall recovery times.
Such is the potential for collaborative working in the medical field that Google's life sciences division is working with Johnson & Johnson's medical device company, Ethicon, to develop surgical robots that use artificial intelligence. The two conglomerates are investigating how advanced sensor and imaging technology can complement the knowledge of surgeons in new ways, such as highlighting nerve cells, blood vessels and tumour margins.
Here to help
The future possibilities for human–robot collaboration are almost limitless, and it is clear in the way that the technology is developing that these machines are just here to help. Whether that is helping to increase productivity in manufacturing lines, or supporting surgeons attempting complex procedures, we are only going to benefit from taking friendly robots out of science fiction and into reality.
For more information about Harmonic Drive please go to harmonicdrive.de/en/home.